scholarly journals Alternative glycosylation controls endoplasmic reticulum dynamics and tubular extension in mammalian cells

2021 ◽  
Vol 7 (19) ◽  
pp. eabe8349
Author(s):  
Despoina Kerselidou ◽  
Bushra Saeed Dohai ◽  
David R. Nelson ◽  
Sarah Daakour ◽  
Nicolas De Cock ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Secretion ◽  
Posttranslational Modifications ◽  
Mammalian Cells ◽  
Cell Enlargement ◽  
Guanosine Triphosphate ◽  
Superresolution Imaging ◽  
Functional Aspects ◽  
The Impact ◽  
Hydrolysis Of

The endoplasmic reticulum (ER) is a central eukaryotic organelle with a tubular network made of hairpin proteins linked by hydrolysis of guanosine triphosphate nucleotides. Among posttranslational modifications initiated at the ER level, glycosylation is the most common reaction. However, our understanding of the impact of glycosylation on the ER structure remains unclear. Here, we show that exostosin-1 (EXT1) glycosyltransferase, an enzyme involved in N-glycosylation, is a key regulator of ER morphology and dynamics. We have integrated multiomics and superresolution imaging to characterize the broad effect of EXT1 inactivation, including the ER shape-dynamics-function relationships in mammalian cells. We have observed that inactivating EXT1 induces cell enlargement and enhances metabolic switches such as protein secretion. In particular, suppressing EXT1 in mouse thymocytes causes developmental dysfunctions associated with the ER network extension. Last, our data illuminate the physical and functional aspects of the ER proteome-glycome-lipidome structure axis, with implications in biotechnology and medicine.

scholarly journals Exostosin-1 Glycosyltransferase Regulates Endoplasmic Reticulum Architecture and Dynamics

2020 ◽  
Author(s):  
Despoina Kerselidou ◽  
Bushra Saeed Dohai ◽  
David R. Nelson ◽  
Sarah Daakour ◽  
Nicolas De Cock ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Mammalian Cells ◽  
Super Resolution ◽  
High Energy ◽  
Structural Proteins ◽  
Post Translational Modifications ◽  
Nucleotide Sugars ◽  
Resolution Imaging ◽  
The Impact ◽  
Hydrolysis Of

SUMMARYThe endoplasmic reticulum (ER) is a central eukaryotic organelle with a tubular network made of hairpin proteins linked by hydrolysis of GTP nucleotides. Among post-translational modifications initiated at the ER level, glycosylation is the most common reaction. However, our understanding of the impact of glycosylation on ER structure remains unclear. Here, we show that Exostosin-1 (EXT1) glycosyltransferase, an enzyme involved in N-glycosylation, is a key regulator of ER morphology and dynamics. We have integrated multi-omics data and super-resolution imaging to characterize the broad effect of EXT1 inactivation, including ER shape-dynamics-function relationships in mammalian cells. We have observed that, inactivating EXT1 induces cell enlargement and enhances metabolic switches such as protein secretion. In particular, suppressing EXT1 in mouse thymocytes causes developmental dysfunctions associated to ER network extension. Our findings suggest that EXT1 drives glycosylation reactions involving ER structural proteins and high-energy nucleotide sugars, which might also apply to other organelles.

scholarly journals Differential Effects of Endoplasmic Reticulum Stress-induced Autophagy on Cell Survival

2006 ◽  
Vol 282 (7) ◽  
pp. 4702-4710 ◽  
Author(s):  
Wen-Xing Ding ◽  
Hong-Min Ni ◽  
Wentao Gao ◽  
Yi-Feng Hou ◽  
Melissa A. Melan ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Endoplasmic Reticulum Stress ◽  
Cell Survival ◽  
Cancer Cells ◽  
Mammalian Cells ◽  
Cellular Response ◽  
Brefeldin A ◽  
Human Colon ◽  
The Impact

Autophagy is a cellular response to adverse environment and stress, but its significance in cell survival is not always clear. Here we show that autophagy could be induced in the mammalian cells by chemicals, such as A23187, tunicamycin, thapsigargin, and brefeldin A, that cause endoplasmic reticulum stress. Endoplasmic reticulum stress-induced autophagy is important for clearing polyubiquitinated protein aggregates and for reducing cellular vacuolization in HCT116 colon cancer cells and DU145 prostate cancer cells, thus mitigating endoplasmic reticulum stress and protecting against cell death. In contrast, autophagy induced by the same chemicals does not confer protection in a normal human colon cell line and in the non-transformed murine embryonic fibroblasts but rather contributes to cell death. Thus the impact of autophagy on cell survival during endoplasmic reticulum stress is likely contingent on the status of cells, which could be explored for tumor-specific therapy.

scholarly journals Characterization of X- box binding protein 1(XBP1) and BiP functions and investigation their roles in YHV replication in P. monodon

2021 ◽  
Vol 20 (4) ◽  
Author(s):  
Piyawadee Rugsanit ◽  
◽  
Pongsopee Attasart ◽  
Apinunt Udomkit ◽  
Witoon Tirasophon ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Amino Acid ◽  
Mammalian Cells ◽  
Binding Protein ◽  
Amino Acid Residues ◽  
Total Change ◽  
Yellow Head Virus ◽  
Black Tiger Shrimp ◽  
Tiger Shrimp ◽  
The Impact

Abstract Eukaryotic cells have mechanisms to cope with stress in endoplasmic reticulum (ER) called unfolded protein response (UPR). In this study, we characterized putative X-box DNA binding protein1 (XBP1) and Binding protein (BiP) cDNAs from black tiger shrimp (Peneaus monodon). When the shrimp were infected with Yellow head virus (YHV), the levels of XBP1 and BiP mRNA transcripts were elevated approximately 8 and 55 folds, respectively. In normal shrimp, the putative XBP1 (XBP1u) was predicted to encode a protein with 283 amino acid residues. When shrimp were infected with YHV, portion of cDNA with 17 nucleotides intron elimination (XBP1s) was observed. The elimination caused alteration of its translational frame. The predicted protein from this is 469 amino acids in length with total change in its amino acid sequence downstream of the intron. Functional analysis of these XBP1 proteins in mammalian cells clearly showed that overexpression of P. monodon XBP1s was capable of activating the transcription rate of mammalian UPR responsive genes (BiP, ERdj4 and P58IPK). Finally, the impact of XBP1 and BiP on YHV multiplication in black tiger shrimp was investigated by RNAi approach. Knocking down either XBP1 or BiP expression efficiently inhibited YHV replication. Therefore, these two components in the UPR pathway may be an interesting target for anti YHV development in the future. Keywords: Endoplasmic reticulum, siRNA, Stress-inducible genes, Transcriptional regulation

Use of Uranium-Labeled Antibodies for Electron Microscopic Localization of Various Antigens in Mammalian Cells

1967 ◽  
Vol 25 ◽  
pp. 136-137
Author(s):  
J. P. Petrali ◽  
E. J. Donati ◽  
L. A. Sternberger
Keyword(s):  
Endoplasmic Reticulum ◽  
Hela Cells ◽  
Mammalian Cells ◽  
Specific Antiserum ◽  
Electron Microscopic ◽  
E Coli ◽  
Cytoplasmic Membranes ◽  
Viral Progeny ◽  
Ultrathin Sections ◽  
Electron Microscopic Localization

Specific contrast is conferred to subcellular antigen by applying purified antibodies, exhaustively labeled with uranium under immunospecific protection, to ultrathin sections. Use of Seligman’s principle of bridging osmium to metal via thiocarbohydrazide (TCH) intensifies specific contrast. Ultrathin sections of osmium-fixed materials were stained on the grid by application of 1) thiosemicarbazide (TSC), 2) unlabeled specific antiserum, 3) uranium-labeled anti-antibody and 4) TCH followed by reosmication. Antigens to be localized consisted of vaccinia antigen in infected HeLa cells, lysozyme in monocytes of patients with monocytic or monomyelocytic leukemia, and fibrinogen in the platelets of these leukemic patients. Control sections were stained with non-specific antiserum (E. coli).In the vaccinia-HeLa system, antigen was localized from 1 to 3 hours following infection, and was confined to degrading virus, the inner walls of numerous organelles, and other structures in cytoplasmic foci. Surrounding architecture and cellular mitochondria were unstained. 8 to 14 hours after infection, antigen was localized on the outer walls of the viral progeny, on cytoplasmic membranes, and free in the cytoplasm. Staining of endoplasmic reticulum was intense and focal early, and weak and diffuse late in infection.

TMCC3 localizes at the three-way junctions for the proper tubular network of the endoplasmic reticulum

2019 ◽  
Vol 476 (21) ◽  
pp. 3241-3260
Author(s):  
Sindhu Wisesa ◽  
Yasunori Yamamoto ◽  
Toshiaki Sakisaka
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Mammalian Cells ◽  
Coiled Coil ◽  
Transmembrane Domains ◽  
Domain Family ◽  
Coiled Coil Domain ◽  
U2os Cells ◽  
Er Membrane

The tubular network of the endoplasmic reticulum (ER) is formed by connecting ER tubules through three-way junctions. Two classes of the conserved ER membrane proteins, atlastins and lunapark, have been shown to reside at the three-way junctions so far and be involved in the generation and stabilization of the three-way junctions. In this study, we report TMCC3 (transmembrane and coiled-coil domain family 3), a member of the TEX28 family, as another ER membrane protein that resides at the three-way junctions in mammalian cells. When the TEX28 family members were transfected into U2OS cells, TMCC3 specifically localized at the three-way junctions in the peripheral ER. TMCC3 bound to atlastins through the C-terminal transmembrane domains. A TMCC3 mutant lacking the N-terminal coiled-coil domain abolished localization to the three-way junctions, suggesting that TMCC3 localized independently of binding to atlastins. TMCC3 knockdown caused a decrease in the number of three-way junctions and expansion of ER sheets, leading to a reduction of the tubular ER network in U2OS cells. The TMCC3 knockdown phenotype was partially rescued by the overexpression of atlastin-2, suggesting that TMCC3 knockdown would decrease the activity of atlastins. These results indicate that TMCC3 localizes at the three-way junctions for the proper tubular ER network.

МАРКЕТИНГОВІ АСПЕКТИ ФУНКЦІОНУВАННЯ ЛІТЕРАТУРНИХ КОНКУРСІВ ТА ПРЕМІЙ

2020 ◽  
pp. 90
Author(s):  
O. Bondar
Keyword(s):  
Publishing House ◽  
Target Audience ◽  
Point Of View ◽  
Information Support ◽  
Literary Field ◽  
Non Profit ◽  
Functional Aspects ◽  
The Media ◽  
Literary Prizes ◽  
The Impact

<p><em>In this study, I have collected and summarized the functional aspects of a literary prize, contest, and rating, which indicate their affiliation with the marketing complex of the publishing house for the first time. For this purpose, I have analyzed and summarized the common concepts of the functioning of literary prizes and contests as advertising tools for publishing activity. Because the previous studies are only focused on the fact of the impact of the prize on the promotion of editions but do not explain it, these aspects have been considered and introduced by me from the book production’s point of view. I investigated that the prizes and the contests in the literary field are effective marketing tools, which meet many publisher’s needs at the same time and can be considered a non-profit form of capital. I have reviewed the works of other authors, who accept that the economic success of the book is rising if the author is a winner of the literary prize or contest. I have found out that the book prize activates the demand for the book, and the literary contest is a tool to track the reader’s reaction to a future publication. In this way, literary prizes and contests can be considered as a way of conducting a marketing dialogue with the target audience. I have focused on the information support of literary national and international prizes and contests by the media, which attracts attention to the book and forms the reader’s interest. The literary prizes and contests are also considered as a way of exploring trends and their changes, familiarization the popular genres among the target audience and fixation the current choice of modern readers. Literary prizes and contests motivate the authors to improve their literary excellence, are the source of new authors and works, and assist in increasing sales of books. However, further research is recommended.</em></p><strong><em>Key words:</em></strong><em> book prize, book rating, literary contest, literary prize, functions of the literary prizes.</em>

scholarly journals Baicalin Represses Type Three Secretion System of Pseudomonas aeruginosa through PQS System

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1497
Author(s):  
Pansong Zhang ◽  
Qiao Guo ◽  
Zhihua Wei ◽  
Qin Yang ◽  
Zisheng Guo ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Mammalian Cells ◽  
Secretion System ◽  
Chinese Herbs ◽  
Infection Model ◽  
Lung Pathology ◽  
Promising Alternative ◽  
The Impact

Therapeutics that target the virulence of pathogens rather than their viability offer a promising alternative for treating infectious diseases and circumventing antibiotic resistance. In this study, we searched for anti-virulence compounds against Pseudomonas aeruginosa from Chinese herbs and investigated baicalin from Scutellariae radix as such an active anti-virulence compound. The effect of baicalin on a range of important virulence factors in P. aeruginosa was assessed using luxCDABE-based reporters and by phenotypical assays. The molecular mechanism of the virulence inhibition by baicalin was investigated using genetic approaches. The impact of baicalin on P. aeruginosa pathogenicity was evaluated by both in vitro assays and in vivo animal models. The results show that baicalin diminished a plenty of important virulence factors in P. aeruginosa, including the Type III secretion system (T3SS). Baicalin treatment reduced the cellular toxicity of P. aeruginosa on the mammalian cells and attenuated in vivo pathogenicity in a Drosophila melanogaster infection model. In a rat pulmonary infection model, baicalin significantly reduced the severity of lung pathology and accelerated lung bacterial clearance. The PqsR of the Pseudomonas quinolone signal (PQS) system was found to be required for baicalin’s impact on T3SS. These findings indicate that baicalin is a promising therapeutic candidate for treating P. aeruginosa infections.

Sign in / Sign up

Export Citation Format

Share Document